Detailed characterization of pulmonary vascular anatomy in one or more portions, such as in an organ, of a person or other living being has important applications for the diagnosis and management of a variety of diseases, including adult pulmonary arterial hypertension, pulmonary embolus, and neonatal persistent pulmonary hypertension. Proper characterization of the vascular tree structure aids in clinical decision-making, assessment of therapeutic efficacy, and evaluation of novel therapies. Accurate quantification of the vascular tree structure also enhances the ability to understand the biological and biomechanical underpinnings of these diseases and the sequelae of events that lead to disease progression and patient death. By quantifying the morphological features of the vascular tree, including the number of branches, number of branch generations, length and average radius of each branch, bifurcation angles, and vessel tortuosity, one can compute the total vascular volume, histograms of branch radii and lengths, and distribution of blood volume among branch radii and generations. Such data, particularly over a period of time, aids in the assessment of disease progression, treatment efficacy, or both
Generally, processing of 3-Dimensional medical imaging data, such as is produced by Computed Tomography, is used to characterize vascular anatomy. Vessel segmentation has been used chiefly to gather information on the number or branches, number of bifurcations, and branch length and volume. The use of large through-plane voxel dimensions (i.e., relatively thick image slices) and patient motion during pulmonary imaging lead to false apparent connections between neighboring but independent vascular trees. Both conditions result in neighboring vessels that blur into the same voxel, thereby making them appear to be contiguous in the image set.